Writing fractal shaders is great fun, agreed. I found mip mapping introduced artefacts around discontinuities in the texture coordinates - this was doing orbit

Writing fractal shaders is great fun, agreed. I found mip mapping introduced artefacts around discontinuities in the texture coordinates - this was doing orbit trap texturing, but the UVs in the described method would have similar discontinuities. The artefacts can be reduced with a bit of care, iirc